Package delivery companies pick up millions of packages daily from thousands of locations over a large geographical area and transport them, primarily by track and airplane, to a correspondingly large number of scattered destinations. To meet a rigorous schedule and provide accurate deliveries, a package delivery company must use automated transfer systems to match incoming packages with proper outgoing transport headed for the packages' destinations. Because deliveries are time sensitive, the sorting equipment must be very fast, yet provide gentle handling of packages.
Belt and roller conveyor systems have often been used in package sorting systems to move packages from incoming loading docks to outgoing transport. A initial sort of packages traveling along a conveyor may be accomplished by diverting packages from the conveyor based on their destinations, or based on their size or another characteristic.
To automate handling of articles in conveyor systems, conveyor diverter assemblies of various types have been developed. Roller bed diverters are shown in U.S. Pat. No. 4,798,275 to Leemkuil et. al., and U.S. Pat. No. 4,174,774 to Bourgeois. Another approach has been to swing a diverter arm diagonally into the path of oncoming packages, which follow the angle of the arm into a side output destination. In some prior systems, an on-edge continuous belt is mounted on vertical-axis pulleys to move around the diverter arm. The movement of the belt moves the packages toward the output point. Examples of such systems are shown in U.S. Pat. No. 1,729,671 to Bell-Irving et. al., U.S. Pat. No. 4,711,357 Langenbeck et. al., and U.S. Pat. No. 4,364,465 to Kraft et al.
These belted diverter systems have not met the needs of a modern conveyor system operating at high speed, for example, 500 fpm (152.4 meters per min.). At such speeds, a package impacting on a diverter arm, whether belted or not, may be dataaged. Attempts to swing the arm out to knock the package off the conveyor may add to this impact, Also, if the swinging speed is set too fast, the arm may send light packages flying off the conveyor and over the output destination. Thus, there is a need in the art for a diverter system that can divert packages traveling at high speeds safely and reliably.